Resize landcape images

I have a problem with resizing landscape images.
All of my images are uploaded with a height of 600px, eg:
464×600
384×600
608×600
837×600
My slideshow is set up with the following parameters
width: 900px
height: 300px
width management: Responsive
Resize images: yes

This means that I can display the image at a reasonable size and then link to a larger version.

All portrait images are correctly resized to a height of 300px (and widths of 232 and 192).
All landscape images (608×600) and (837×600) are resized to the full width of 900. The height remains at 300 so the bottom is cut off. I would expect them to be resized to 304×300 and 418×300.
If I experiment by reducing the width to say 500px or even 200px, landscapes are still resized to that width but, of course, less cropping takes place.

Any ideas

Andy

https://wordpress.org/plugins/cyclone-slider-2/